1. Field of the Invention
The present invention relates to an optical communication method and an optical remote controller using the same in which infrared rays are employed to remotely control an electric appliance for family use, a television conference, or the like.
2. Description of the Related Art
Recently, optical remote controllers using infrared rays have been broadly applied to various fields as infrared ray remote controllers for such apparatuses as a television, an audio system, and an air conditioner.
Description will be given of an optical remote controller of the prior art. For example, according to a first conventional example described in JP-A-3-62637, there has been proposed a communication method using a micro computer which handles a plurality of receiving sections to select therefrom a receiving section operating in a favorable communication state.
FIG. 18 shows in a block diagram the configuration of an optical remote controller in the first conventional example. A reference numeral 501 indicates a light emitting section of the controller. The section 501 moves, for example, in a direction from a point A to a point B as denoted by an arrow mark in the diagram. A numeral 502 designates a main section of the controller furnished with a micro computer 503 and first to fourth light receiver sections 504 to 507.
Operation of the first conventional example will be next described. In operation, when the light emitting section 501 is at a position A, the main section 502 selects the first light receiving section 504 for communications. In this situation, when the section 501 is moved to a position B, the first light receiving section 504 is beyond a zone or range to receive infrared rays from the light emitting section 501. Consequently, a communication error will be detected or the number of errors detected by a data check using parity bits or the like will be increased. To overcome this difficulty, the micro computer 503 selects the second light receiving section 505 for communications. When another communication error occurs or a predetermined error rate is exceeded in data communications, the micro computer 503 automatically and sequentially selects another light receiving section until communication is desirably achieved. With the light emitting section 501 set to the position B, when it is assumed that a favorable communication state is obtained for the third light receiving section 506 selected as above, the apparatus uses the section 506 for the subsequent communications. However, when a communication error is again detected, the fourth light receiving section 507 is selected for further communications.
In a second conventional example described, for example, in JP-A-5-34812, a plurality of light receiving sections are arranged such that the camera direction is controlled in association therewith.
FIG. 19 is a front view of an optical remote controller in the second conventional example. In this construction, a camera 601 is fixedly disposed on a camera setting section 602, which is attached on a supporting plate 605 of a tripod 603. The camera setting section 602 rotatably moves in the vertical and horizontal directions to control the direction of the camera 601. The section 602 includes light receiving sections 604a to 604e.
FIG. 20 is a block diagram showing the structure of a control section of the optical remote controller according to the second conventional example. Signals transmitted from a light emitting section 606 are received by the light receiving sections 604a to 604e. A judge section 607 checks intensity of the received light and then an instruction value calculating section 608 accordingly issues to a motor driver 609 an instruction to drive a motor 610. As a result, the driver 609 drives the motor 610 to actuate the camera setting section 602.
In the optical remote controllers respectively of the first and second conventional examples, the sensing precision with respect to the direction of a subject is, for example, about five degrees (5.degree.).
However, the first conventional example is attended with a problem that after an occurrence of a communication error, data cannot be attained until it is decided there is another light receiving section suitable for communications. Furthermore, after the light emitting section 501 is moved, the light receiving sections 504 to 507 used up to this point in time are beyond the zone to appropriately receive infrared rays from the light emitting section 501, which increases a probability of occurrence of communication errors. Consequently, the communication data is required to include check data such as parity bits.
In addition, according to the second conventional example, the light receiving sections 604a to 604e also move together with the camera 601 and the camera setting section 602. This restricts detecting directions of light rays of the light receiving sections. To expand the zone or range of detecting the direction of light rays, there have been disadvantageously required a large number of light receiving elements.
As for the operational requirements, for the reason described above, the signals are required to be continuously emitted from the light emitting section during the sequence of operations until the light receiving sections are oriented toward the direction of the light emitting section.